Fundamental step of processing color light-sensitive materials generally include a color-developing step and a silver-removing step. In the color-developing step, exposed silver halide is reduced with a color-developing agent to produce silver and, at the same time, the oxidized color-developing agent in turn reacts with a color former (coupler) to give a dye image. In the subsequent silver-removing step, silver having been produced in the color-developing step is oxidized with an oxidant, then converted to a soluble silver complex by the action of a fixing agent, thus being dissolved away.
In addition to the above-described fundamental steps, actual development processing involves various auxiliary steps such as treating the color light-sensitive material in a hardening bath, a stopping bath, an image-stabilizing bath, a water-washing bath, etc. for the purpose of maintaining the photographic and physical qualities of the image, or for improving the preservability of the image.
In recent years, accelerated processing, or shortening of processing time, has been strongly desired. Particularly, shortening of a silver-removing step, which occupies almost a half of the total processing time, has been a subject of great interest to those devoted towards decreasing development time.
Heretofore, as a means for accelerating the silver-removing step, a bleach-fixing solution containing a ferric aminopolycarboxylate complex salt and a thiosulfate as described in German Pat. No. 866,605 has been known. However, when allowed to coexist with the thiosulfate having reducing power, the ferric aminopolycarboxylate originally having a weak oxidizing power (bleaching power) undergoes such a serious reduction of bleaching power that it is extremely difficult to fully remove silver from a high-speed, high-silver content color photographic light-sensitive material. Thus, this means for accelerating the silver-removing step is scarcely used in practice. On the other hand, another technique for increasing the bleaching power comprises adding various bleaching accelerators to a bleaching bath, a bleach-fixing bath, or a pre-bath thereof. Examples of these bleaching accelerators include various mercapto compounds, as described in U.S. Pat. No. 3,893,858, British Pat. No. 138,842, Japanese Patent Application (OPI) No. 141,623/78 (the term "OPI" as used herein means an "unexamined published application"), disulfido bond-containing compounds, as described in Japanese Patent Application (OPI) No. 95,630/78, thiazolidone derivatives, as described in Japanese Patent Publication No. 9,854/78, isothiourea derivatives, as described in Japanese Patent Application (OPI) No. 94,927/78, thiourea derivatives, as described in Japanese Patent Publication Nos. 8,506/70 and 26,586/74, thioamide compounds, as described in Japanese Patent Application (OPI) No. 42,349/74, and dithiocarbamic acid salts as described in Japanese Patent Application (OPI) No. 26,506/80, etc.
However, even the addition of these bleaching accelerators to a bleaching bath, a bleach-fixing bath or a pre-bath thereof still fails to fully accelerate the processing to a desirable speed. Thus, further improvements in acceleration have been desired.
On the other hand, as a technique for enhancing sensitivity of silver halide color photographic materials, a technique of using tabular grains has been developed. This technique is useful for enhancing sensitivity without spoiling image quality. However, this method has the defect that silver cannot be fully removed therefrom by a conventional silver-removing process, and further, that this technique causes an increased occurrence of magenta stains.